In the manufacture of machine elements having complex surfaces of revolution, such as ball bearing races, it has been customary to rough out the surface on a screw machine, to heat treat the race, and then to grind the ball track. One of the difficulties of this procedure is that the number of times that the workpiece must be handled, i.e., introduced and removed from a machine tool and transported from one machine to another. Furthermore, the heat treatment tends to distort the workpiece and to upset any precise geometric relationship that might have existed between the parts of the surface. To restore such relationships, it is necessary not only to grind the important part of the surface (ball track) but the other surfaces also (seal grooves). The excessive handling and the multiplicity of machining operations cause the finished cost of the workpiece to be quite high. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a grinding machine for forming any contoured surface of revolution on a rough workpiece.
Another object of this invention is the provision of a grinding machine for producing the roller track and seal groove on a bearing race directly from a blank bushing.
A further object of this invention is the provision of a grinding machine for plunge grinding the ball track and seal grooves on a ball bearing race in an uninterrupted operation.
It is another object of the instant invention to provide a grinding machine for plunge grinding a complex internal surface of revolution very accurately despite severe stock removal.
A still further object of the invention is the provision of a grinding machine for abrasive machining of contoured surfaces of revolution with excellent repeatability of geometry and finish.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.